Hosted VoIP for start-ups & small businesses?

A friend asked me yesterday what benefits hosted VoIP has for start-ups and small businesses. So I've had a go at outlining the more obvious reasons below:

• You can get a phone number without having to get a new BT line installed for it;
• It can grow with you, as it is scaleable to as many users and phone numbers as you want. You can easily add new services or remove unwanted services each month to match your current needs;
• Your number is not tied to one address, so you can move your business from home office, to serviced offices to leased offices all without changing your contact details & with no downtime;
• You can answer your company phone as if you're in the office, whether you're at home, on your mobile, in the office or even abroad;
• It should include all these features: hunt groups; voicemail; welcome messages; voice menus; hold music; conference calls; call transfers; call redirects; & out of hours messages;
• Calls between your VoIP enabled office and home workers are free;
• Cheap to set up and low monthly cost;
• No expensive PBX box is needed in your office or home, or expensive maintenance & support contract for said box;
• Great local support from us.